{"nhtsa_id":10201215,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2021-09-28","date":"2021-09-08","document_id":"SF636","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN","mfr_system":null,"summary":"Field Service Campaign for Western Star 49X Differential Lock - Parameter Update. Vehicles may automatically disengage the differential lock without warning when vehicle speed reaches 25 mph.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2021/MC-10201215-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2021/MC-10201215-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10201215","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"WESTERN STAR","model":"49X","year_from":2021,"year_to":2022,"match":null,"vehicle_ids":[]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}